Patient with Spontaneous Respirations Intubated Patient
  • Monitor clinical status closely (WOB, anxiety, single breath count, airflow, mental status, pulse pressure, pulsus paradoxus)
  • Do NOT intubate based on blood gas
  • Ominous Signs
    • Silent chest - no air flow or pneumothorax
    • Poor air movement - may be sign of impending respiratory failure
    • Normal or high pCO2 in a tachypneic patient - may be sign of early muscle fatigue and impending respiratory failure
     
  • Allow permissive hypercarbia (pH >7.25)
  • Use low respiratory rates and short inspiratory times to minimize hyperinflation and air trapping
  • Ensure each breath returns to baseline
  • Maintain adequate oxygenation
  • PEEP settings controversial - Consider low PEEP (0-5) b/c patient is already hyper expanded versus matching patient's auto peep on the ventilator

General management principles

  1. Hydration - Patient will need fluid resuscitation because has been hyperventilating and has increased insensibles
  2. Continuous albuterol - Use 0.25-0.5mg/kg/hr (usually 10 -20 mg/hr). May need to do back to back nebs while waiting for pharmacy and RT to set up.
  3. Oxygen - Use as carrier for nebulizer, will not suppress respiratory drive.
  4. Steroids - Give 2 mg/kg methylprednisolone as a bolus, then start 0.5mg/kg Q 6 hrs
  5. Mg bolus - Give 25-40 mg/kg bolus (over 30 mins), may repeat if needed. Thought to help relax smooth muscle

Other considerations

  • Sub-Q Epinephrine - β agonist, often used if no IV access. Dose is 0.01 mg/kg of the 1:1000 solution.
  • Terbutaline (β-agonist) - Continuous infusion, typical dosing range 0.5-2 mcg/kg/min
  • Ipratropium bromide (anti-cholinergic) - Usually Atrovent 2 puffs Q 4-6 hrs
  • Theophylline (methylxanthine) - Give loading dose, followed by continuous infusion. Monitor levels (goal 10-20)
  • Heliox - Used to reduce air flow resistance in small airways, limited by degree of hypoxemia in pt. 70/30 or 80/20
  • Ketamine - If sedation is needed, preferred drug due to bronchodilating properties, typical dosing range 0.1-2 mg/kg/hr
  • Zithromax - Most common infectious trigger for asthma is Mycoplasma or Chlamydia pneumoniae
  • Anesthesia (inhaled anesthetics) and ECMO (VV) (for refractory cases)